Mobile devices such as cellular telephones, smart phones, and tablets, use operating systems to manage hardware and provide common services for installed software applications. Unlike personal computer (“PC”) operating systems in which applications can access and share resources with other applications, mobile operating systems typically isolate applications from each other for reasons of security and resource management. Isolating applications in this manner, however, limits the potential functionality of the mobile device. In particular, the ability to provide user-specific content in diverse applications, which can enhance the user experience, can be limited if those applications cannot share data with each other.